Nuclear magnetic resonance spectrometer

ABSTRACT

A sample intake means for a nuclear magnetic resonance spectrometer having a sample tube including a sample to be analyzed, a holder for supporting the sample tube, a guide provided between an inlet of the spectrometer case and a nuclear magnetic resonance signal detector for guiding the holder, strings for hanging the holder from a cover provided on the inlet so that the holder moves up and down with the opening and closing motion of the cover.

[ Mar. 12, 1974 United States Patent [191 Utsumi et al.

[ NUCLEAR MAGNETIC RESONANCE FOREIGN PATENT R P SPECTROMETER s 0 AP LICATIONS [75] Inventors: Yoshiharu Utsumi; Katsunobu Abe,

both of Katsuta, Japan Primary ExaminerMichael J. Lynch [73] Assignee: Hitachi, Ltd., Tokyo, Japan [22] Filed: Dec. 27, 1971 [21] Appl. No.: 211,877

ABSTRACT [30] Foreign Application Priority Data A sample intake means for a nuclear magnetic reso- Dec. 25 1970 45-117615 lance spectrometer having a Sample tube including a sample to be analyzed, a holder for supporting the 52 US. 324/05 R Sample tube a guide Provided between an inlet of the 51 Int. Cl. G01n 27/78 spewometer Case and a nuclear magnetic resonance 58] Field of searchmm 324/05 R 05 A, 05 AH signal detector for guiding the holder, strings for hang- Y 324/05 MA ing the holder from a cover provided on the inlet so that the holder moves up and down with the opening and closing motion of the cover.

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INVENTORS YOSHIHARU UTsUMJ KAT'SUNOBU ABE Ciro/La QMtOuLQQC 4) H112 ATTORNEYS NUCLEAR MAGNETIC RESONANCE SPECTROMETER BACKGROUND OF THE INVENTION The present invention relates to a sample intake means for introducing into or removing a sample to be analyzed from a nuclear magnetic resonance spectrometer.

In a conventional intake means for a spectrometer, a sample is brought into a nuclear magnetic resonance signal detecting position between pole pieces of a permanent magnet or an electromagnet by manual adjustment performed by an operator. An air space large enough to insert the hand, therefore, must be provided as far as the vicinity of the detecting position. Thus, the thermal stability of the magnet is subject to deterioration thereby. These are some of the problems to be considered in the design of such an arrangement.

The resonance magnet for this purpose requires a stability and a uniformity in the magnetic field which is as high as possible. In the permanent magnet, the magnetomotive force is remarkably influenced by the temperature. Normally, the permanent magnet, therefore, must be kept at a temperature (1) of, for instance, 35C., and the permitted variation of the temperature At mustbe kept at not higher than 2 X lO X t.

A magnetic shield to eliminate the influence of the external magnetic field is also required. Further, it is necessary to reduce the leakage flux as much as possible.

It is, therefore, important to make the size of the sample intake means small as possible so as to transmit as little heat as possible into the magnet. Further, it is a problem to provide the sample intake hole in the magnetic path so as not to disturb the magnetic field.

SUMMARY OF THE INVENTION An object of the present invention is to provide a new sample intake means, in which the above-mentioned inconveniences are eliminated.

Another object of the invention is to provide the sample intake means which can set the sample smoothly into a nuclear magnetic resonance signal detecting po- BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic view of the nuclear magnetic resonance spectrometer;

FIGS. and 2b are a diagram of a sample intake means according to an embodiment of the present invention and a diagram showing a partial detail thereof, respectively;

FIG. 3a shows a longitudinal cross-sectional view for explaining the operation of the embodiment in FIG. 2a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT nates a cover of the guide 4. The magnet 1 is surrounded by an adiabatic material 6 in order to keep its temperature constant. Further, a magnetic shield material 7 surrounds the adiabatic material 6 to prevent the device from being influenced by an external magnetic field. The whole arrangement is enclosed within a case 8.

The present invention particularly relates to a part of the spectrometer comprising the sample tube 3, the guide 4 and the cover 5. The details of the embodiment of the present invention will be explained hereinafter.

In FIG. 2a, numerals l, 2, 3, 4, and 5 designate the 1 same basic elements as are shown in FIG. 1. Further a nozzle 9 is provided under the lower portion of the guide 4 to blow compressed air to blades 10 of an air turbine, wlHcFis sliowh Hi detailHFIG. 272. The air turbine comprises the blades 10 driven by compressed air and stabilizing blades 11, and the turbine is 'rotatably supported on a bearing member mounted .on the upper plate of the detector so that the com pressed air from the tube 9 will make the sample tube 3 rotate at about 3,000 r.p.m., which rotation reduces the influence owing to any inequalities in the magnetic field. The purpose of the stabilizing blade I1 is not only to provide a stabilizing of the rotation, but also to provide a stable support of the air turbine in a sample tube holder 12. It is, therefore, a desire that the number of stabilizing blades provided be three or more.

The holder i is slidable in tube 4 and is suspended by two hanging strings 13. The ends of the strings outside the guide 4 are connected to each other and are fixed at an open edge of the cover 5 through a spring 15. Numeral 14 denotes an axle ofa hinge of the cover 5.

FIG. 3 shows a cross-sectional view of the above mentioned device. In this figure, numerals 20 and 21 designate a lower stopper and an upper stopper for the guide 4, respectively.

The operation of the device above described is as follows. The cover 5 opens and shuts by swinging about the axle 14 of the hinge, and the holder 12 moves up and down in response to the opening and closure of the cover 5. When the cover Sis open, the holder 12 moves up to the upper end of the guide 4. With this upward movement of the holder 12, the sample tube 3 is removed from the detector 2, as shown by the dotted line in FIG. 2a. When the cover 5 is closed, the holder I2 moves down to the lower end of the guide 4. Then, the stabilizing blade I] becomes free from the contact with the holder 12. The sample tube 3 is rotated by a compressed air from the nozzle 9.

When the cover 5 is opened, the holder 12 moves up to guide 4 to the upper stopper 21 and stops there. The

holder 12 is then held there by the tension of the spring 15. Then, the stabilizing blades 11 are in frictional contact with the holder 12, as shown by chain lines in FIG. 3. When the cover 5 is closed, the holder 12 is supported by the lower stopper 20. However, due to the spacing between the holder 12 and the support for the sample tube 3 on the detector at this time, the stabilizing blades 11 become free from the contact with the holder 12, so that the air turbine is rotated by the compressed air from the nozzle 9. Accordingly, the sample tube 3 is also rotated during a measurement.

if the holder 12 is made from aluminum, which is light and is good conductive material, the holder 12 produces an eddy current in itself, since it links with a leakage flux of the magnet 1 when moving down along the guide 4. The eddy current generates in the holder 12 a braking force, and this eddy current becomes large as the holder 12 approaches the lower stopper 20. A setting of the sample tube 3 on the detector 2, therefore, is performed smoothly without any break-down of the sample tube 3 and the detector 2.

Having thus described the present invention, it is obvious that various modifications within the knowledge of workers in the art may be utilized without departing therefrom.

It is to be understood also that although the invention has been described with specific reference to a particular embodiment thereof, it is not to be so limited, since changes and alterations therein may be made which are within the full intended scope of this invention as defined by the appended claims.

What is claimed is:

1. In a nuclear magnetic resonance spectrometer having an exterior case with an inlet for a sample tube, magnetic field generating means enclosed in said case and a nuclear magnetic resonance signal detector for receiving said sample tube including a sample to be analyzed, a sample intake arrangement comprising a holder for supporting said sample tube, guide means provided between said inlet of said spectrometer case and said nuclear magnetic resonance signal detector for guiding said holder during movement thereof between said inlet and said detector, a cover hinged to said case to cover said inlet, and linkage means connected between said holder and said cover for moving said holder up and down within said guide means in a coordinate manner with opening and closing motion of said cover.

2. A sample intake arrangement for a nuclear magnetic resonance spectre-meter having a case, magnetic field generating means enclosed in said case and a nuclear magnetic resonance signal detector for receiving a sample tube including a sample to be analyzed, comprising a holder for supporting said sample tube, guide means provided between an inlet of said spectrometer case and said nuclear magnetic resonance signal detector for guiding said holder during movement thereof between said inlet and said detector, a cover provided on the inlet of the case, and linkage means for moving said holder up and down within said guide means in a coordinate manner with opening and closing motion of said cover further including a lower stopper mounted on said guide means for supporting said holder at one end thereof and supporting means for supporting said sample tube independently of said holder when said holder is supported by said lower stopper of said guide means so that said sample tube becomes free to move with respect to said holder.

3. A sample intake arrangement according to claim 2 wherein said sample tube is supported in said holder by an air turbine having a portion including driving blades extending outside of said holder, said supporting means including an air nozzle positioned for alignment with said driving blades when said holder is supported on said lower stopper.

4. A sample intake arrangement according to claim 3 wherein said air turbine includes a plurality of stabilizing blades which frictionally engage with said holder when said holder is moved up said guide means.

5. A sample intake arrangement according to claim 4 wherein said linkage means comprises a pair of strings, one end of each string being fixed on said holder, the other end being secured to an open edge of said cover.

6. A sample intake arrangement according to claim 5 wherein said pair of strings is connected to said cover by way of a coil spring.

7. A sample intake arrangement according to claim 1 wherein said linkage means comprises a pair of strings, one end of each string being fixed on said holder, the other end being secured to an open edge of said cover.

8. A sample intake arrangement according to claim 1 wherein said holder is made from a light-weight, conductive material.

9. A sample intake arrangement according to claim 1 wherein said sample tube is supported in said holder by an air turbine having a portion including driving blades, and further including air supply means for driving said turbine in rotation.

10. A sample intake arrangement according to claim 9 wherein said air turbine includes a plurality of stabilizing blades which frictionally engage with said holder when said holder is moved up said guide means. 

1. In a nuclear magnetic resonance spectrometer having an exterior case with an inlet for a sample tube, magnetic field generating means enclosed in said case and a nuclear magnetic resonance signal detector for receiving said sample tube including a sample to be analyzed, a sample intake arrangement comprising a holder for supporting said sample tube, guide means provided between said inlet of said spectrometer case and said nuclear magnetic resonance signal detector for guiding said holder during movement thereof between said inlet and said detector, a cover hinged to said case to cover said inlet, and linkage means connected between said holder and said cover for moving said holder up and down within said guide means in a coordinate manner with opening and closing motion of said cover.
 2. A sample intake arrangement for a nuclear magnetic resonance spectro-meter having a case, magnetic field generating means enclosed in said case and a nuclear magnetic resonance signal detector for receiving a sample tube including a sample to be analyzed, comprising a holder for supporting said sample tube, guide means provided between an inlet of said spectrometer case and said nuclear magnetic resonance signal detector for guiding said holder during movement thereof between said inlet and said detector, a cover provided on the inlet of the case, and linkage means for moving said holder up and down within said guide means in a coordinate manner with opening and closing motion of said cover further including a lower stopper mounted on said guide means for supporting said holder at one end thereof and supporting means for supporting said sample tube independently of said holder when said holder is supported by said lower stopper of said guide means so that said sample tube becomes free to move with respect to said holder.
 3. A sample intake arrangement according to claim 2 wherein said sample tube is supported in said holder by an air turbine having a portion including driving blades extending outside of said holder, said supporting means including an air nozzle positioned for alignment with said driving blades when said holder is supported on said lower stopper.
 4. A sample intake arrangement according to claim 3 wherein said air turbine includes a plurality of stabilizing blades which frictionally engage with said holder when said holder is moved up said guide means.
 5. A sample intake arrangement according to claim 4 wherein said linkage means comprises a pair of strings, one end of each string being fixed on said holder, the other end being secured to an open edge of said cover.
 6. A sample intake arrangement according to claim 5 wherein said pair of strings is connected to said cover by way of a coil spring.
 7. A sample intake arrangement according to claim 1 wherein said linkage means comprises a pair of strings, one end of each string being fixed on said holder, the other end being secured to an open edge of said cover.
 8. A sample intake arrangement according to claim 1 wherein said holder is made from a light-weight, conductive material.
 9. A sample intake arrangement according to claim 1 wherein said sample tube is supported in said holder by an air turbine Having a portion including driving blades, and further including air supply means for driving said turbine in rotation.
 10. A sample intake arrangement according to claim 9 wherein said air turbine includes a plurality of stabilizing blades which frictionally engage with said holder when said holder is moved up said guide means. 